1. Field of the Invention
The present invention relates to a photosensitive resin composition, and more particularly to a positive photosensitive resin composition suitable for application in the field of micro electronics and developable with an aqueous alkaline solution and a method for manufacturing a semiconductor device using the composition.
2. Description of the Related Art
In the application of micro electronics, polymers showing durability at high temperature are generally widely known. Precursors of polymers such as polyimides and polybenzoxazoles (PBO) can be made photoreactive with suitable additives. These precursors are converted to desired polymers by known techniques such as exposure to high temperature. Accordingly, in order to manufacture protective layers, heat insulating layers and relief structures of highly heat-resistant polymers, the polymer precursors have been used.
U.S. Pat. No. 4,371,685 discloses a positive photosensitive resin composition comprising an alkali-soluble PBO precursor and a diazoquinone photoactive compound. The diazoquinone compound prevents the PBO precursor from being dissolved in an aqueous salt. After exposure, the diazoquinone compound is photolyzed, and converted to an indene carboxylic acid which accelerates dissolution of the PBO precursor in an alkaline developing solution.
Further, JP-T-2002-526795 (the term “JP-T” as used herein means a published Japanese translation of a PCT patent application) discloses a composition comprising a PBO precursor partially capped with a diazoquinone compound.
The photosensitive resin composition comprising such a PBO precursor is a system in which it is difficult to obtain the sufficient difference in the rate of dissolution between an unexposed area and an exposed area, and there is a problem with regard to image performances such as sensitivity, film loss and resolution. Further, in a process in which heat curing is performed at about 300° C. after pattern formation, coloration occurs in some cases. This coloration poses a problem in a subsequent packaging process.